Electromagnetically-actuated apparatus



Dec. 4', 1923. 1,476,363'

M. HERKLOTZ ELECTROMAGNETI CALL! ACTUATED APPARATUS Filed March 19, 1923A :i v 27;

InVc-antor i Max Her'klobz,

- Hls Attor' ney. I

iiatented Dec. 4, 1923.

UNITED STATES 1,476,363 PATENT OFFICE.

MAX HERKLOTZ, OF BERLIN, GERMANY, ASSIGNOR T GENERAL ELECTRIC COMPANY, ACORPORATION OF NEW YORK.

ELECTROMAGNETICALLY-AGTUATED APPARATUS.

Application filed March 19, 1923. Serial 110. 628,197.

To aZl whom it may concern:

Be it known that I, MAX HERKLoTz, a citizen of the German Republic,residing at Berlin, Germany, have invented certain new and usefulImprovements in Electromag' netically-Actuated Apparatus (for which Ihave filed an application in Germany, March 2, 1922)., of which thefollowing is a specification.

My invention relates to electromagnetically actuated apparatus which isenergized by an electrical condition varying over a very wide range andhas for its object the provision of means whereby the range of operationof the apparatus may be increased.

My invention is of particular value in connection with vibratoryregulators of the well known Tirrill type. In these regulators one ofthe vibratory contacts is actuated by a magnet which is energized by theexciter voltage. Since this voltage varies over a wide ran e between noload and full load, considerahle difiiculty has been encountered indesigning a relay which will operate satisfactorily over this entirerange.

In accordance with my invention I provide suitable devices whichcooperate with the electromagnetically actuated apparatus so that theenergizatlon of the apparatus varies at a different rate than theelectrical condition which energizes the apparatus. In one embodiment ofmy invention I connect in parallel with the apparatus, a device having aresistance which varies inversely with respect to the variations in theelectrical condition energizing said apparatus. Such a device may be aresistor having a. negative temperature coefficient or an electron tubeconnected so that the resistance of the tube decreases with an increasein the electrical condition energizing the apparatus.

In another embodiment of my invention, I obtain the same result byproviding the apparatus with a second exciting winding which opposes themain exciting winding and which is energized in accordance withvariations in the electrical condition which energizes the main excitingwinding.

My invention will be better understood from the following descriptiontaken in connection with the accompanying drawing in which Fig. 1 showsone embodiment of my invention, and Figs. 2 and 3 show modifications ofthe arrangement shown in Fig. 1.

Referring to Fig. 1, 1 represents a generator, the voltage of which isto be regulated. 2 represents an exciter which is provided with a shuntfield winding 3, the excitation of which is controlled by a regulator 4of the well known Tirrill type comprising a control magnet 5 connectedso as to be energized in accordance with the voltage or other electricalcondition of the generator 1, and a control magnet 6 connected so as tobeenergized in accordance with the voltage of the exciter 2. 7represents the differentially wound relay magnet of the regulator whichhas one winding 8 permanently connected across the exciter 2 and anotherwinding 9 aranged to be connected across the eXc-iter 2 when the maincontacts 10 of the regulator are in engagement. The

contacts 11 of the dilferential relay magnet 7 control a shunt circuitaround a resistance 12 in the shunt field circuit of the exciter.

The arrangement heretofore described is old and well known in theregulator art. As stated above, the.range of such a regulator is limitedby the construction of the magnets 6 and 7 which cannot be designed soas to respond to a wide variation in the voltage impressed thereon.

In the embodiment of my invention shown in Fig. 1, I increase the rangeof the regulator by connecting in parallel with the coil of the magnet6, a resistor 13 of suitable material such as boron having a negativetemperature coefficient. Preferably a resistor 14 which may have apositive temperature coeflicient is connected in series with the coil ofthe magnet 6 and the resistor 13. In like manner a resistor 15 having anegative temperature coefficient is connected in parallelf'with thecoils 8 and 9 of the difierential relay 7 and a resistor 16, which mayhave a positive temperature coeflicient, is

connected in series with the coils 8 and 9 and the resistor 15.

Since the resistance of the resistors 13 and 15 decreases as the voltageof the exciter 2 increases, a smaller portion of the total currentsflowing through the resistors 14 and 16 flows through the coil of themagnet 6 and through the coils 8 and 9 of the differential relay 7respectively so that a variation in the voltage of the exciter does notproduce a proportional change in the ampere turns of. the magnets 6 and7.

By means of the resistors 13 and 15, it

is possible to regulate the voltage of the generator over a very muchgreater range than when they are not used.

Instead of using a resistor of a material having a negative temperaturecoeflicient,

any other suitable device may be used, the

resistance of which varies inversely with the variable electricalcondition to which the particular electrical apparatus is subjected. Forexample, an electron tube such as a kenotron may be used. Fig. 2'shows amodification of a portion of the system shown in Fig. 1 in which akenotron 17 is substituted for the resistor 13. The kenotron comprises aplate 18 connected to the positive terminal of the exciter and afilament 19 connected in parallel with the coil of the ma et 6. Aresistor 20 is connected in series between the positive terminal of theexciter 2 and the filament so that theplate 18 is more positive than thefilament. At low voltages the resistance of the plate circuit of thetube is high so that very little current flows through the tube. As theexciter voltage increases, the temperature of the filament increases andthe plate becomes more positivewith. respect to the filament so that agreater portion of the current through the resistor 14 flows through thetube. Consequently 'a variation in the exciter voltage does not producea proportional variation in the ampere turns of the magnet 6.

In the modification of Fig. 1 shown in Fig. 3, the field winding 3 ofthe exciter is connected to an auxiliary exciter 25 which isself-excited. The contacts 11 of thedifferentially wound magnet 7control a short circuit around a resistor .26 in the field circuit ofthe exciter 25. The magnet 6 of the regulator in this embodiment of myinvention is provided with three windings 27, 28 and 29. The winding 27is connected across the exciter 25. The winding 28 is connected to asource of constant potential such as a pilot generator 30 driven in anysuitable manner. As shown, the rotors of the exciter 25 and pilotgenerator 30 are mounted on the same shaft. The winding 29 is connectedacross a shunt 31 in the field circuit of the generator 1 so that theexcitation of this winding is dependent on the magnitude of the excitingcurrent of the generator 1 which in turn depends upon the voltage of theexciter 25. The windings 27 and 28 are arranged so that they aid eachother and oppose winding 29. Preferably windings 28 and 29 are soproportioned that when the generator 1 is running at no load these twowindings neutralize each other and only the ampere turns of the winding27 are effective to operate the magnet. As the load on the generatorincreases, the excitation of the generator automatically increased bythe regulator in the well known manner. Since the excitation of thewindage-vanes ing 28 remains constant and the excitation of the winding29 increases, the resultant ampere turns of the three windings is lessthan the ampere turns of winding 27. Therefore the action of this devicesecures the same result as the arrangement shown in Fi s. 1 and 2.

IVhile I have shown and described several modifications of my invention,it is evident that my invention is not limited thereto and I seek tocover in the appended claims all those modifications of my inventionthat fall within the true spirit and scope of my in--' vention.

What I claim as new and desire to secure by Letters Patent of the UnitedStates, 1s:

1. In a regulating system for a dynamo electric machine, an exciterconnected to the field winding of said machine, an electromagnet forcontrolling the excitation of said exciter having a winding so connectedthat it is energized in accordance with the voltage of said exciter, andmeans connected so as to be afi'ected by variations in the voltage ofthe exciter for causing the energization of said electromagnet to varyat a difi'erent rate than the exciter voltage varies.

2.111 a regulating system for a dynamo electric machine an exciterconnected to the field winding of said machine, an electromagnet forcontrolling the excitation of said exciter having a winding so connectedthat it is energized in accordance with an electrical condition of saidexciter, and means so connected and arranged that the current throughsaid means is controlled by the electrical condition of the exciter inaccordance with which said winding is energized and the change incurrent through said means produced by said electrical condition effectsa smaller proportional change in the ampere turns of said electromagnet.

3. In a regulating system for a dynamo electric machine, an exciterconnected to the field winding of said machine, and an electromagnet forcontrolling the excitation of said exciter having a winding 'soconnected that it is energized in accordance with an electricalcondition of said exciter,

nected that it is energized in accordance with an electrical conditionof said exciter, a second winding supplied from a constant potentialsource of current, and a third winding so connected that its excitationvaries in accordance with the variations in the electrical conditioncontrolling the excitation of said first mentioned winding, said thirdwinding being wound differentially with respect to the other twowindings and arranged so that at no load the combined magnetizing effectof said second and third windings is substantially zero.

5. In a regulating system for a dynamo electric machine, an exciterconnected to the field winding of said machine, a second exciterconnected to the field winding of said first mentioned exciter, a sourceof constant potential, and an electromagnet for controlling theexcitation of said second exciter having a winding connected so that itis energized in accordance with the v0ltage of said second exciter, asecond winding energized in accordance with voltage of said constantpotential source, and a third winding connected so as to be energized inaccordance with the current supplied to the field Winding of saidmachine, said third winding being wound differentially with respect tothe other two windings and arranged so that at no load the combinedmagnetizing effect of said second and third windings is substantiallzero.

In witness whereof, have hereunto set my hand this 12th day of February,1923.

MAX HERKLOTZ.

